The invention relates to a viewing apparatus having an image intensifier which is arranged between an objective and an ocular. An output screen faces the ocular, and an alignment member with an alignment marker support displaceable in two orthogonal directions with respect to the output screen is arranged between the output screen and the ocular.
In a known viewing apparatus of the kind mentioned in the opening paragraph (known from European Patent Application No. 0 133 729), the output screen of the image intensifier consists of a flat fibre optics plate provided with a phosphor layer. Flat spacer elements separate the phosphor layer from the alignment marker support in the alignment member. Imperfections in the optical system of the image intensifier lead to a curved image, which can be compensated for by means of comparatively expensive electron-optical means.